Method of and apparatus for controlling spooling motors



July 18, 1944. w. BERTHOLD ET AL 2,353,639

METHOD OF AND APPARATUS FOR CONTROLLING SPOOLING MOTORS Filed Nov. 28,1941 FULL REEL EMPTY REEL F/aE [XACT T0741. LOAD 7080 LOW MOTORTdkQl/far M07017 2 F763 ANGULAR VELOCITY JTART PER/0D f MR5 .srzso w/msup a CAISI'AN Y ,w/Rs sum N0 sur o/v CAPSTAI/ q km E T 1 I T I I RELAY4 J M F H SETTING TIME RELAY or C76!!! 7 6751.5 C :64! Cglb' C YCLE 756E 3%M1 rm: DELAY RELAY cwsea IMIHWORS 3 F164 W. BERTHOLD 3 w. w. REA 4 7rms- ATM/W 7 Patented July 18, 1944 METHOD OF AND APPARATUS FOR CON-TROLLING SPOOLING MOTORS Wolf Berthoid, Weehawken, and Wilson W. Rea,Chatham, N. J., assignors to Western Electric Company, Incorporated, NewYork, N. Y., a corporation of New York Application November 28, 1941,Serial No. 420,768

14 Claims.

This invention relates to a method of and apparatus for controllingspooling motors and more particularly to a method of and apparatus forcontrolling the takeup spool operation of a wire drawing machine.

In the operation of modern high speed wire drawing machines used in themanufacture of fine wire, it has been the practice, in some instances,to permit the wire on the last step of the wire drawing capstan to slipslightly in order in accordance with the p esent m t o to preventbreakage of the wire. In order to per- Fig. 2 shows, diagrammatically,the speed mit this slip, it is essential that the takeup mechto quecurve of the Spooler motor; anism does not apply excessive tension tothe Fi 3sh w mm i y, t wire pee wire and that the average wire speed beheld me Curve, and lower than the surface speed of the last capstan.Fig. 4 s m tically, the wire ten- Furthermore, there have been continuedatsion-time curve. tempts to draw greater lengths of wire without In thedrawing, the numeral 5 designates a breakage in the wire, resulting inthe use of rela pp SD00} On which there is Wound a pp y tively largespools having drums of small diamof relatively coarse Wire 6- u a y munted eter so that the spool will hold a large amount djacent the supp yS9 5 is a -S p d uide of fine wire. In apparatus of this type, great 7for Wire fYOm the pp y SDOOI 5 t0 difliculty has been experienced incontrolling the t fi st e d aw ng die mounted in a die block speed ofthe takeup spool for the wire drawing he W e l be Withdrawn fXOm the ppapparatus so that there is the least possible tend- D00 5 by a wiredrawing capstan 9, driven v y & ency for the takeup spool to applyexcessive tendraw motor Suitable guide rOliBYS H being Sign t th iprovided for guiding the wire 6 in its passage It is an object of thepresent invention to probet een the capstan 9 and the dies in the dievide an improved method of and apparatus for block obtaining a selectedaverage tension on strands After t Wire has been passed t o the dies instrand handling machi 3c in the die block 8, wrapped a predeterminednum- In accordance with one embodiment of the ber of times around thecapstan 9 a d passed invention, the speed of the wire between the lastOver the guide e s it iS directed from the step of the wire drawingcapstan and the takeup last D o the capstan 9 to a u de r01 6! l2- spoolis ccntrolled by varying the torque of the Cooperating With thfi guideroller '2' is a movable spooler motor in cycles between a relativelyhigh guide roller [3, mounted upon a tension or upp value and arelatively low value, to maintain a Cushioning arm Which s, in turn, ped at controlled slip on the last capstan and thereby W The arm 14,which s p r s t e uide roller maintaining the tension in the wirebetween the l3, is normally held in predetermined p ion capstan andtakeup spool substantially constant by cooperating p in 5 and IT andcarries a throughout most of the cycle of the apparatus, 40 cond guideroller Ill. The decrease in motor torque is initiated, in ac- The Wire,after being passed around One Of the eo an it t present th by by passmgidler guide rollers on the cushionin arm i4 is rtio of th resistance ofh poofing t r directed to an idler roller I9, back to the other rotorcircuit under control of a tension arm beroller 0h and down 150 t e d sr butor 24. The tween th capstan of the wire drawing apparatus idlerroller I9 is mounted on a cushioning arm and the takeup spool, whichtension arm will close 29, Similar to the arm the arm 20 being D acircuit to a slow to release or time delay relay Oiled at 2| and beingheld in its normal pos t n when the tension on the wire reaches apredetery coope Springs 22 and 3- With this armined point. The slow torelease or time delay Iangemeht, the Cushioning arms y be moved relay,upon being energized, will cut out a portio on relatively closetogether, at which time there will of the resistance in the rotorcircuit for a definite short period of time and since the motor normallyoperates on the portion of its speed torque curve where both speed andtorque are descending, the by-passing of part of its resistance willreduce its be a comparatively short length of wire between the fixedidler l2 and a distributor 24, or when the tension on the Wire isreleased somewhat, a relatively large amount of wire may be held under adefinite tension between the roller l2 and the distributor 24 due to thedisplacement of the cushioning arms 14 and Ill and the guide rollerscarried by them away from each other. The distributor 24, which is showndiagrammatically, distributes the wire over the face of the takeup spool25 mounted upon a shaft 25 and adapted to be driven by a spooler motor21. The shaft 25 also has mounted on it an electromagnetic type ofclutch 25, which, upon energization, will connect the shaft 15 directlyto a sheave 29, thereby to connect the shaft 25 through a drivingelement 30 to a shaft 41, which interconnects the motor II and capstan9, the shaft 3| being provided with a driving sheave 32. This justdescribed magnetic clutch and driving connection serves to connect thecapstan and takeup spool during the starting periods of the machine,suitable interlocks being illustrated diagrammatically at 33. Theseinterlocks may be of the type disclosed in the co-pending application ofC. O. Haase No. 292,787, filed August 31, 1939, now Patent No.2,266,861, issued December 23, 1941, or may be of any other suitabletype which will serve to positively interconnect the takeup spool andcapstan during the periods of acceleration on the starting of theapparatus. Any suitable means may be utilized for controlling theapparatus during deceleration, but since it does not pertain to thepresent invention, it has not been shown.

After the interlock illustrated diagrammatically at 33 has controlledthe starting of the apparatus and the capstan and takeup spool havereached their normal operating speeds, the electromagnetic clutch 28will be deenergized and the motor 21, which is preferably a 3 phaseinduction motor, will control the speed of the takeup spool or reel 25.The motor 21 has its stator field supplied with current through theleads 34, 35 and 36 and normally has the resistances 60, ii and 42connected in its rotor circuit through the break contacts of a relay 43,which may be of the slow to release type or may be a time relay settableto release after a predetermined interval upon being energized. In thediagram of Fig. 1, this device has been shown in the form of a slow torelease relay in order to simplify the disclosure, but it will beunderstood that any suitable time delay relay may be substituted for theslow to release relay. The relay 43 has one side of its windingconnected to ground at 44 and has the other side of its windingconnected to one terminal of a highly sensitive switching device 54comprising contacts 45 and 45. The con tact 45 is connected to thewinding of the relay 43 and is positioned to be closed by an extendingportion 41 of the cushioning arm 14 when the tension in the wire betweenthe distributor 24 and guide roller 12 reaches a predeterminedrelatively high value. The contact 46 of switch 54 is connected togrounded battery at 48 and when the switch 54 closes, the groundedbattery at 48 will be connected through the winding of the relay 43 toground at 44 to energize the relay 43, thus by-passing part of theresistance of the rotor circuit of motor 21.

By reference to Fig. 2, it will be seen that the range of operation ofmotor 21, which, as pointed out hereinbefore, is a 3 phase inductionmotor, is in that portion of the speed torque curve where both the speedand the torque are descending. Since the load torque is also descendingat this time, the by-passing of a portion of the resistance of the rotorcircuit of the motor will result in a decrease in the torque output ofthe motor, thereby to decrease the speed of the motor, create slip andlower the tension in the wire I between the roller 12 and the takeupspool 25.

Since it is desirable to operate the apparatus with a slight slip on thelast pass oi the wire drawing capstan, the control of the speed relationand consequent tension between the capstan and the takeup spool must bemaintained within a relatively close range and, with the apparatusdescribed hereinbefore, this is accomplished by by-passing a portion oithe resistance in the rotor circuit of the takeup motor for definitetime intervals. After the spooling motor or takeup motor 21 and drawingmotor it have been started in operation and have reached their normaloperating speed, the slip on the last step of the wire drawing capstan 9will be maintained within the desired range by by-passing a part oi theresistance of the rotor circuit of the spooler motor 21 at variableintervals under control of the switch 54, which will be actuated by thecushionlng arm 14 when the tension in the wire reaches a predeterminedvalue. This operation is illustrated diagrammatically in Fig. 3, whereinthe time cycles of the apparatus have been illustrated and designatedcycles 1 to 6, inclusive. By reference to Fig. 4, it will be seen thatthe tension in the wire is substantially constant over a major portionof the winding operation and when the slip at the last capstan is takenup, the tension will rise rapidly to a predetermined value, effectingclosure of switch 54 and introducing a definite period of decelerationof the takeup spool. In order to illustrate this portion of theoperation, the curve illustrating wire speed has been exaggerated; thatis, the decrease in the time during which the resistance is normal inthe rotor circuit of motor 21 has been shown as decreasing quite rapidlyto bring out the fact that while the time interval during which part ofthe resistance of the rotor circuit of the spooler motor is by-passed isconstant, the time intervals during which the resistance is in the rotorcircuit of the spooler motor decreases gradually as the takeup spool 25goes from an empty to a full condition. It is believed to be apparentfrom the foregoing that after the apparatus has gone through itsstarting period of acceleration and reached its normal operating speed,the increase in tension to a predetermined point in the wire between thecapstan and takeup spool will cause the closure of switch 54 and theconsequent bypassing of a portion of the resistance of the rotor circuitof the spooler motor 21 and that this bypassing of resistance will bemaintained for a definite set interval, depending upon the setting ortime delay characteristics of the relay 43, whereupon the resistancewill automatically be cut back into the rotor circuit and will remain inthe rotor circuit a variable period of time until the accumulation ofwire between the rollers 13, I8 and I9 is taken up by the takeup spooland the cushioning arms I4 and 20 are moved close enough together tocause the portion 41 of arm 14 to again close switch 54. In this manner,the tension in the wire between the capstan and takeup spool and theconsequent degree of slip of. the wire on the last pass of the capstanwill be varied within a definite predetermined range.

Although a specific embodiment of the invention has been describedhereinbefore, it will be understood that modifications thereof may bemade without departing from the invention, which is defined by theappended claims.

What is claimed is:

1. A method of controlling the tension of a strand in a takeup mechanismwhich comprises increasing the tension until it reaches a predeterminedupper limit and then decreasing the tension a predetermined amount for apredetermined time, and repeating these steps to obtain a selectedaverage tension.

2. The method of controlling the speed of a takeup spool motor relativeto an associated material working apparatus which comprises applying arelatively high torque to the motor of the takeup spool tending to placethe material under tension between the working apparatus and takeupspool, decreasing the resistance of the circuit of the spool motor inresponse to a predetermined tension in the material, and maintainingsaid lower resistance in the spool motor circuit for a definite lengthof time, thereby to alternately apply a high and low torque to thespool.

3. A method of controlling the range of tension of a strand in a takeupmechanism which comprises automatically varying the speed of the strandbetween fixed high and low values, initiating the low speed condition atintervals in response to a predetermined increase in tension on thestrand, and maintaining said low speed condition for predetermineddefinite intervals.

4. A method of controlling the range of tension of a strand in a takeupmechanism which comprises automatically varying the speed of the strandbetween high and low values, initiating the low speed condition atintervals in response to a predetermined increase in tension on thestrand, and maintaining said low speed condition for the same intervalof time after each initiation thereof.

5. A method of controlling the tension or a strand between a strandworking apparatus and a takeup mechanism which comprises maintaining avariable supply of strand between the working apparatus and takeupmechanism, reducing the amount of said supply to a predetermined amount,then increasing said supply at a predetermined rate for a definite timeinterval, and repeating these steps alternately to obtain a tensionwithin a selected range.

6. In a strand takeup mechanism, a takeup spool, a motor for drivingsaid spool, a tension arm movable in response to tension in the strand,

means for varying the torque of the motor, andmeans actuated by thetension arm for rendering the means for varying the torque of the motoroperative for a definite fixed interval or time.

7. In a strand takeup mechanism, a takeup spool, a motor for driving thespool, means responsive each time the strand is subjected to apredetermined amount of tension for decreasing the torque output of themotor by a predetermined amount, and means for maintaining the tensionresponsive means effective for a predetermined interval of time eachtime it is rendered effective by the tension of the strand reaching saidpredetermined amount.

8. In a strand takeup mechanism, a takeup spool, a motor for driving thetakeup spool, resiliently supported means for maintaining a loop ofstrand adjacent the takeup spool. means operable by said resilientlysupported means upon a predetermined decrease in the size of said loopfor decreasing the torque of said motor, and means associated with saidlast mentioned means for maintaining said last-mentioned means operativefor a predetermined time interval.

9. In a strand takeup mechanism, a takeup spool, a motor for driving thetakeup spool, resiliently supported means for maintaining a loop ofstrand adjacent the takeup spool, means actuated by the resilientlymounted means in response to a predetermined tension in the loop forreducing the torque of the motor to increase the size of said loop, andmeans for maintaining said last mentioned means operative for apredetermined length of time.

10. In a strand takeu'p mechanism, a takeup motor operable in theportion of its speed-torque curve where torque and speed are increasing,said motor having a rotor resistance of a definite value, a takeup spooldriven by said motor, guiding means for supporting a variable supply ofstrand adjacent said takeup spool, means actuated by the guiding meansfor by-passing a portion of the resistance of the rotor circuit of themotor to decrease the torque of the motor, and means for holding thelast mentioned means operative for a predetermined length of time toincrease the supply of strand supported by guiding means.

11. A methodof controlling the tension of a strand in a takeup mechanismwhich comprises driving the takeup mechanism at a relatively high speeduntil the tension in the strand reaches a predetermined upper limit andthen decreasing the speed of the takeup mechanism to a predeterminedfixed speed for a fixed time, and repeating these steps to obtain aselected average tension in the strand.

12. In a strand takeup mechanism, a takeup spool, a motor for drivingsaid spool, a tension arm movable in response to tension in the strand,means for varying the speed at which the motor drives said spool, andmeans actuated by the tension arm for rendering said last mentionedmeans operative for a definite interval of time each time the tensionarm actuates it.

13. In a strand takeup mechanism, a takeup spool, a drive motor fordrivingthe takeup spool,

, means for maintaining a loop of strand acfiacent the takeup spool,means operable by the means for maintaining a loop of strand when thesize of the loop is decreased a predetermined amount for decreasing thespeed of the motor, and means associated with said last-mentioned meansfor maintaining said last-mentioned means operative for a predeterminedtime interval.

14. In a strand takeup mechanism, a takeup spool, a motor for drivingsaid takeup spool, re-

siliently supported means for maintaining a loop of strand adjacent thetake-up spool, means operable by said resiliently supported means when apredetermined decrease in the size of said loop occurs for decreasingthe speed of said motor, and means associated with said last-mentionedmeans for maintaining said last mentioned means operative for apredetermined time interval/ WOLF BERTHOLD. WILSON W. REA.

